text: In the tablet-pressing process, it is important that all ingredients be fairly dry, powdered or granular, somewhat uniform in particle size, and freely flowing. Mixed particle sized powders may separate outsegregate during manufacture due to their different densities. This can result in tablets with poor drug or active pharmaceutical ingredient (API) content uniformity, but granulation should prevent this. Content uniformity ensures that the same API dose is delivered with each tablet.
  Some APIs may be compressed into tablets as pure substances, but this is rarely the case; most formulations include pharmacologically inactive ingredients (excipients):
  * Usually a binder is added to help hold the tablet together and give it mechanical strength. A wide variety of binders may be used: some common ones are lactose, dibasic calcium phosphate, sucrose, corn (maize) starch, microcrystalline cellulose, povidone polyvinylpyrrolidone and modified cellulose (for example, hydroxypropyl methylcellulose and hydroxyethylcellulose).
  * Often, an ingredient is also needed to act as a disintegrator to aid tablet dispersion once swallowed, releasing the API for absorption. Some binders, such as starch and cellulose, are also excellent disintegrators.